Well completion apparatus



June 5 M. L. CROW ETAL 3,386,515

WELL COMPLETION APPARATUS 2 Sheets-Sheet l Filed Dec. 5, 1965 F/gJZINVENTORS 4/0464 1. oeau/ 59 J05 0. FOJZE'R MAP/01V 0. 60kt" June 4,1968 M. L. CROW ETAL WELL COMPLETI ON APPARATUS Filed Dec. 5, 1965 lK//////// //\f/// /V f I I I 2 Sheets-Sheet 2 INVENTORS MAR/0M 0. A716M5 v BYME-MM 3P United States Patent 3,386,515 WELL COMPLETIONAPPARATUS Morgan L. Crow, Joe D. Foster and Marion 1). Kilgore,

Dallas, Tex., assignors to Dresser Industries, Inc., Dallas, Tex., acorporation of Delaware Filed Dec. 3, 1965, Ser. No. 511,547 6 Claims.(Cl. 166-120) ABSTRACT 0F THE DISCLOSURE A casing packer assemblyincluding a string of casing suspended in a well bore, a formationpacker attached to the casing string and arranged to be set against thewall of the well bore, and a slip joint incorporated in the casingstring above the packer whereby thermal changes in the casing areabsorbed in the slip joint without disturbing the packer or imposingstresses on the casing.

This invention is concerned with a well completion method and apparatusand is particularly concerned with a well completion method andapparatus wherein an oil well may be completed and the casing settherein without the necessity of cementing or other means of rigidlysupporting the casing with relation to the well bore so that a slipjoint may be incorporated in the well casing to compensate for expansionthereof due to excessive temperature rise in the well bore.

Although useful in the completion of any well wherein temperaturevariations are encountered, the present invention is especiallyapplicable in wells which are subjected to thermal recovery methods.

In recent years so-called thermal recovery has been widely resorted towherein hot fluids or vapors are introduced from the surface into theproducing formation to lower the viscosity of the oil therein, resultingin an increase in productivity of the formation.

This has been done by several methods. A common method is to injectsaturated or super-saturated steam into the well bore at temperatures of600 F. or greater. Another method is introduction of hot vapors or oil,products of combustion, or heated inert gases at a temperature up to1000 F.

Such superheated fluids are usually injected into a selected injectionwell to supply the hot media to the formation, and the lowered viscosityof oil is produced from production wells in communication with theformation. In either event the problem to which this invention isaddressed is present.

Another method of thermal recovery is that which is called in situcombustion.

In this method a fire is actually ignited in the producing formation andis sustained by an introduction of combustion-supporting fuel. The heatgenerated by the in situ combustion passes through the formation toraise the pressure thereof, lower the viscosity of the oil therein, andthereby increase the production therefrom. In the employment of thismethod excessive rise in temperature creates a problem of undueexpansion of the casing.

The linear co-etficient of thermal expansion for steel is approximately6.9 l0 -6 inches per degree Fahrenheit. Thus, for an average rise intemperature of 100, every 1000 ft. length of easing would undergo athermal expansion or extension in length of approximately 8.3 inches.For a 500 F. increase in temperature over a length of 5000 it, thisextension would amount to approximately 207 inches, or slightly over 17ft. It will be apparent that the disruptive stresses to which the casingwould be subjected, if rigidly cemented into the well bore, and noprovision was made to compensate for ex- Patented June 4, 1968 pansion,would in many instances be more than the casing strength couldwithstand.

Therefore, strictly from a mechanical standpoint alone, assuming thatthe casing could be cemented in place, the present invention solves agreat problem caused by the recent advent of thermal recovery.

However, the problem is accentuated by the fact that cements capable ofwithstanding the higher temperatures of thermal recovery processes havenot been developed as yet, thereby placing an upper limit on thetemperature which can be employed in such process.

Inasmuch as the present invention eliminates the necessity of cementingthe casing in place and provides means for compensating for expansion ofthe casing, the thermal recovery process can be practiced to the fullestextent.

It is, therefore, a primary object of the invention to provide a methodand apparatus of positioning and anchoring a casing in a well withoutcementing or otherwise rigidly securing it to the well bore.

Another object of the invention is to provide method and means forpositioning a casing in a well bore in such a manner as to allow thecasing to expand in response to temperature rise without placing unduestress on the casing.

A still further object of the invention is to provide a combinationpacker and slip joint positioned in the casing string wherein the packermay be set to provide a combination seal and anchor against the wall ofthe well bore, and wherein the casing is permitted to expand tocompensate for excessive rise in temperature in the well bore withoutplacing undue stress on the casing.

A further object of the invention is to provide a com bination packerand anchor to be set against the wall of the well bore which may beexpanded and set by hydraulic force admitted through a tool lowered on atubing string into the casing.

Another object of the invention is to provide a combination formationpacker and slip joint which may be lowered into the well in retracted,unexpanded position, and which has shear elements therein, which may bebroken, to permit the packer to be set by hydraulic force injected fromthe surface, and the slip joint to be disengaged for expansion inresponse to temperature rise in the well bore.

A still further object of the invention is to provide a formation packerwhich may be anchored and sealed against the formation by hydraulicpressure injected from the surface, and which may be disengaged,retracted, and retrieved from the well when desired.

A general object of the invention is to provide method and apparatuswhich permits the maximum employment and benefits derived from thethermal recovery process.

Other and further objects of the invention will become apparent uponreading the detailed specification hereinafter following and byreferring to the drawings annexed hereto.

A suitable embodiment of the invention is shown in the attacheddrawings, wherein,

FIGURE I is a schematic cross-sectional elevational view of thecombination of elements making up the in vention, as it would appearwhen installed in an oil well bore,

FIGURE II is a cross-sectional elevational view of the expansion jointin telescoped position,

FIGURE III is a fragmentary cross-sectional elevational view showing thefrangible connection between the mandrel and the external shell of theexpansion joint in expanded position,

FIGURE IV is a cross-sectional elevational view of the packer inunexpanded position, showing the hydraulic setting tool positioned inthe bore of the packer preparaa tory to applying hydraulic pressure tothe packer to expand and set same; and

FIGURE V is a cross-sectional elevational view of the packing elementemployed with this invention, showing the details of constructionthereof.

Numeral references are employed to indicate the various parts shown inthe drawings and like numerals indicate like parts throughout thevarious figures of the drawings.

FIGURE I shows schematically a generalized layout of the variouselements of this invention in a well bore 1, which is drilled throughvarious sedimentary or unproductive earth strata, and a relativelycompact, well consolidated and impervious caprock 2, into or through aproducing formation 3. It is desirable that the packer P be set againsta formation of type indicated at 2 in order to provide the bestcombination seal and anchor, as hereinafter indicated.

A surface string 4 is cemented in the upper portion of the well bore, asindicated at 5, to protect surface strata and fresh water producingstrata.

The surface string 4 supports 'a casing head 6, which, in turn, supportsat producing casing string 7, as by mating threads 8.

A- telescoping expansion joint I, described in detail in connection withFIGURES II and III, is attached to the lower end of the productioncasing 7 and positioned in such a telescoped relationship that increasesin temperature, causing longitudinal expansion of the production string7, can be absorbed therein to compensate for such expansion withoutundue stress to the casing.

A formation packer P, described in detail in connection with FIGURES IVand V, is positioned and set in the wall of the well bore through theimpervious cap rock 2, and supports said expansion joint I in itsexpanded position.

In the event more than one producing zone, separated by imperviouslayers such as 2, are encountered, it is obvious that the combination ofthe present invention could be extended, and a like combinationformation packer P and expansion joint I could be positioned and usedfor each of said production zones to compensate for thermal expansion ofthe casing between said zones.

Referring now to FIGURES II and III, the expansion joint I consists ofan upper hollow connection 20, having threads 2% therein for connectionto the casing string, and an external tubular shell 21, rigidly attachedto said upper connection 26' by mating threads 22. The sealing rings 23prevent fluid loss or pressure leaks between connection 20 and shell 21.

A lower stop 24 is attached to the exterior sleeve 21 by welding orother suitable means, as indicated at 25, and has an inwardly extendingshoulder 26. Spaced keys 27 are carried by the lower stop 24 and areadapted to engage in spaced, downwardly facing slots 28 when theexpansion joint is in fully extended position (FIGURE III) in order fortorque or rotary motion to be applied therethrough.

The slots 28 are formed on the lower end of a support ring 29, which isattached to the tubular inner mandrel 30 as by welding shown at 31.There is a groove 32 machined in the exterior surface of support ring 29which is positioned to engage shear screws 33 extending through thelower stop 24 to hold the expansion joint I in fully extended positionwhile being run into the well, as shown in FIGURE III. A multiplicity ofseal rings 34 are positioned between the upper end of the support ring29 and the mandrel head ring 35, which is attached to the mandrel 30 bythe mating threads 36.

Referring to the detail drawing of the formation packer P, shown inFIGURES IV and V, an upper connection 40 is adapted to receive inthreaded and supporting engagement the mandrel 30 of expansion joint Iby mating threads 30a.

Attached to the upper connection 40 by the mating threads 41, is apacker head 42. Also attached to upper connection 40 by mating threads43 is a tubular mandrel 44 which extends internally and downwardlythrough the packer P.

Surrounding the mandrel 44 there is a movable head 45, slidably mountedthereon. Seal ring 46 establishes a fluid tight, slidable seal betweenhead 45 and mandrel 44.

Also positioned around the mandrel 44, and between the head 42 andmovable head 45, there is a packing memher, generally indicated at 47.The packing member 47 includes a steel spiral 43 of flat material(FIGURE IV) which has one end attached to the head 42 by the upper capscrew 49, and the other end attached to the movable head 45- by the capscrew 56. Between the convolutions of the spiral 48, there arepositioned a multiplicity of packing rings 51 made of flexible,deformable material, and preferably impregnated with asbestos fibers orother heat resistant material.

The entire packing member 47 is enclosed in a boot 52 made of a flexiblematerial, of asbestos braid or the like, which is suitably impervious tothe action of temperature and well fluids. The boot 52 is attached toheads 42 and 45 at the upper and lower ends by the split rings 53 whichare held in place to the head 42 and movable head 45, respectively, bythe screws 54.

Attached to the movable head 45 by the mating threads 55, is a cylinder56 which is supported in the unset position on cylinder support 57. Thecylinder support 57 is attached about the mandrel 44 by means of snaprings 58 positioned in grooves provided in the wall of the mandrel.

Shear plugs '59 are carried by the cylinder 56 and are engaged in anexternal slot 60 provided in the support 57. The shear plugs 5% areadapted to hold the formation packer P in an extended position whilerunning into the well bore. Shear plugs 59 have a predetermined shearvalue so that they will shear at a predetermined force and allow thesetting of the packer after it has been run into the well.

A piston head 61 is positioned between the mandrel 44 and the cylinder56 in slidable fluid tight relation to each by means of the seal rings61a. The retracted, running position of the piston head 61 is maintainedon the mandrel 44 by the shear plugs 63, which extend through head 61and engage in a groove 64 cut into the outer surface of the mandrel 44-.

There is an upper frusto-conical surface 65 on the piston head 61adapted to carry the toothed wedges 66 which are retained thereon by thesnap ring 67, engaged in a groove about the head 61. Movement upwardlyof the cylinder 56, with relation to head 61 is possible, but thetoothed wedges 66, acting between the frusto-conical surface 65, and theinner wall of cylinder 56 effectively prohibits relative downwardmovement of the cylinder 56 in respect to piston head 61.

The mandrel 44 is further provided with pressure ports 68 through thewall thereof, which are positioned between the movable head 45 and thepiston head 61 through which hydraulic pressure may be applied to thearea between head 45 and piston head 61.

An hydraulic setting tool H is provided which is adapted to be run intothe well on a relatively small, or macaroni, string of tubing 69 fromthe surface of the well. The setting tool H consists of a tubularmandrel 70 upon which is mounted an upper sealing cup 71, facingdownwardly, and a lower sealing cup 72, facing upwardly. Said upper andlower sealing cups are adapted to contain an hydraulic pressuretherebetween. Pressure ports 73 are provided through the wall of thetubular mandrel 70, which communicate with the port 68 in the formationpacker P for the application of hydraulic pressure from the surface ofthe well through tubing 69 to set formation packer P in the mannerhereinafter described.

In running the equipment described in connection with this invention,the expansion joint I is made up on the bottom of the production casingstring 7 and the formation packer P is attached thereto.

The shear plugs 59 of the formation packer P are in place, the packingelement 47, and its connected cylinder 56, are held in the extendedposition thereby, and running clearance is thus provided between thepacker P, and the well bore 1.

The shear plugs 33 of the expansion joint I are engaged in the slot 32(FIGURE III) of the support ring 29 and thereby holds the expansionjoint in the fully extended position for running-in purposes.

It is important that the expansion joint be in this extended positionwhile running, and immediately thereafter, inasmuch as the temperaturein the well at that time is as low as will be met, and compensation forexpansion of the casing string 7 must be provided for when subsequentthermal recovery processes are started to cause the temperature to whichthe casing string is exposed to increase. The length of the strokeprovided by the expansion joint which is necessary to compensate for theexpansion of the casing string can be precalculated by consideringthe'depth to which the equipment is to be run and the expecteddifferential in temperature which the casing string will be subjected.

When the formation packer P has been positioned opposite the imperviouscap rock formation 2, as determined by log readings or other well knownprocedures, the casing string 7 is hung in the well head 6 byconventional means.

After running the packer and expansion joint in the well the hydraulicsetting tool H is run inside of the casing string 7 on a relativelysmall or macaroni tubing string 69 and positioned with the hydraulicports 73 in the running tool mandrel 70 opposite the ports 68 in thepacker mandrel 44 and with the upper and lower sealing cups 71 and 72,respectively, bridging said ports 68 in the packer mandrel.

Hydraulic pressure is then applied from the surface through the macaronistring 69 and acts between heads 45 and 61 to cause the movable head 45to move upwardly relative to the mandrel 44 and thereby compress thepacking element 47 into sealing and supporting engagement with theimpervious formation 2 (FIGURE I). It should be noted that the steelspiral plate 48, which was originally in an extended position, willincrease diametrically as the sealing element 47 is compressed axiallyand will bite into said impervious formation 2 to aiford mechanicalsupport to the packer P.

As the hydraulic force is applied through the ports 68, the shear plugs59 shear at a predetermined shear value, but the shear plugs 63, whichhave a predetermined shear value relatively higher than the plugs 59,are not sheared.

Shear plugs 63, with their higher shear value, are adapted to shear onlywhen the entire mechanism of this combination is retrieved. Plugs 63 maybe sheared by upward pull on the casing string when it is desired toretrieve the packer.

When shear plugs 63 shear, the piston head 61 is released to allowcylinder '56 to move downwardly thereby permitting packing element 47 toextend axially and decrease diametrically so the packer can be retrievedfrom the well on the casing string 7.

In the original unset position of the packer P the shear plugs 33 in theexpansion joint are in place and unsheared. However, after the packer isset, and the thermal cycle has begun, either due to injection of steam,hot vapors, or the production of hot fluids in the formation in aproduction well, the relatively long length of the casing string 7 willincrease in temperature, its length will increase enormously, and theshear plugs 33 will shear, allowing the shell 21 to telescope downwardlyover the mandrel 30 of the expansion joint and compensate for theexpansion of the casing string, as shown in FIGURE II.

It should be noted that this invention can be practiced with or withoutadditional well tools inside of the production casing string 7, such aspackers, valves, tubing,

CIC.

As shown in the schematic drawing of FIGURE I an additional string ofpipe 73 may be run into casing 7 and suspended from well head 6 bymating threads 74, and may 'be sealed to the casing 7 by a packer 75.

It should be further emphasized that in wells containing two or moreproductive zones separated by impervious and well consolidated strata,the invention can be practiced by the addition of an expansion joint andformation packer for each such production zone. In these cases, thestroke of the expansion joints would be calculated according to thelength of each additional assembly, including said expansion joint andpacker and necessary casing.

It will be obvious that other and further embodiments of the inventionmay be devised without departing from the spirit and scope of theappended claims.

Having described our invention we claim:

1. In a well packer useful in a well bore, a head; a tubular mandrelattached to the head; a support ring slidably and sealing disposed aboutthe mandrel in Spaced relationship to the head; a spirally arrangeddeformable packing element disposed about the mandrel between the headand the support ring; a spirally arranged metal wall gripping memberdisposed in the convolutions of said packing element having one endconnected to said head and another end connected to said support ring; acylinder attached to the support ring and extending downwardly about themandrel, there being an annular space between the cylinder and themandrel; anchoring means between the cylinder and the mandrel and beingarranged to permit upward movement of the cylinder with relation to themandrel but preventing downward movement thereof; frangible meansconnecting the cylinder to the mandrel arranged to be broken uponapplication of hydraulic pressure between the ring and the anchoringmeans; and means to admit hydraulic pressure from the mandrel to thearea between the ring and the anchoring means to move said cylinderupwardly to deform said packing element into sealing engagement with thewall of the well bore.

2. Means for completing a well, having a well bore with a producingformation communicating therewith, comprising, a well head attached atthe upper end of the well bore; a string of casing suspended to the wellhead and extending downwardly in the bore; a formation packer attachedto the casing string arranged to be set against the wall of the wellbore above the producing formation; first shearable means holding thepacker in retracted position; an hydraulically actuated means to breakthe said first shearable means and expand the packer into sealing andanchoring engagement with the wall of the Well bore; second shearablemeans to hold the packer in expanded poistion, said second shearablemeans being of higher shear value than said first shearable means; and aslip joint incorporated in the casing string above the packer comprisingtelescoping members arranged to move longitudinally with relationship toeach other in response to thermal expansion of the casing.

3. Means for completing a well, having a well bore with a producingformation communicating therewith, comprising, a wellhead attached atthe upper end of the well bore; a string of casing suspended to the wellhead and extending downwardly in the bore; a formation packer attachedto the casing string arranged to be set against the wall of the wellbore above the producing formation; a slip joint incorporated in thecasing string above the packer comprising telescoping members arrangedto move longitudinally with relationship to each other in response tothermal expansion of the casing; and said packer including a headattached to one of the telescoping members of the slip joint, a tubularmandrel attached to the head, a support ring slidably and sealinglydisposed about the mandrel in spaced relationship to the head, a spiralmember disposed about the mandrel having one end attached to the headand the other end attached to the support ring, packing materialdisposed in the convolutions of the spiral, a sleeve secured to thesupport ring and extending downwardly about the mandrel, there being anannular space between the sleeve and the mandrel, an expander memberdisposed about the mandrel within said annular space, and beingsealingly disposed with relation to the mandrel and the sleeve, anchormeans between the expander member and the sleeve arranged to permitupward movement but not downward movement of the sleeve with relation tothe mandrel, frangible means connecting the sleeve to the mandrel,frangible means connecting the expander to the mandrel, the last-namedfrangible means being shearable at a higher shear value than thefirst-named frangible means, and means to admit hydraulic pressure fromthe mandrel between the expander member and the support ring sufficientto shear the firstnamed frangible means and move the support ring andsleeve upwardly to expand the spiral member and packing material.

4. The combination called for in claim 3 wherein the means for admittinghydraulic pressure between the expander member and the support ringcomprises at least one port through the wall of the mandrelcommunicating with the space between the expander member and the supportring and a hydraulic tool comprised of a support mandrel attachable to atubing string arranged to be lowered into the well from the Surface,said support mandrel being closed at its lower end and having at leastone passage through the wall thereof arranged to be positioned oppositethe port; and spaced seal members on the support mandrel engageable withthe wall of the tubular mandrel above and below the port and passage toconfine and direct hydraulic pressure injected through the tubing stringfrom the surface.

5. In a well packer, a head; a tubular mandrel attached to the head; asupport ring slidably and sealingly disposed bout the mandrel in spacedrelationship to the head; a deformable packing element disposed aboutthe mandrel between the head and the support ring; a cylinder attachedto the support ring and extending downwardly about the mandrel, therebeing an annular space between the cylinder and the mandrel; anchoringmeans between the cylinder and mandrel providing a seal between thecylinder and the mandrel and being arranged to permit upward movement ofthe cylinder with relation to the mandrel but preventing downwardmovement thereof; frangible means connecting the cylinder to the mandrelarranged to be broken upon application of hydraulic pressure between thering and the anchoring means; shearable means conmeeting the anchoringmeans and the mandrel, which shearable means has a higher shear valuethan the frangible means connecting the cylinder to the mandrel; andmeans to admit hydraulic pressure from the mandrel to the area betweenthe ring and the anchoring means.

6. In a well packer, a head; a tubular mandral attached to the head; asupport ring slidably and sealingly disposed about the mandrel in spacedrelationship to the head; a deformable packing element disposed aboutthe mandrel between the head and the support ring; a cylinder attachedto the support ring and extending downwardly about the mandrel, therebeing an annular space between the cylinder and the mandrel; anchoringmeans between the cylinder and the mandrel providing a seal between thecylinder and the mandrel and being arranged to permit upward movement ofthe cylinder with relation to the mandrel thus preventing downwardmovement thereof; frangible means connecting the cylinder to the mandrelarranged to be broken upon application of hydraulic pressure between thering and the anchoring means; and means to admit hydraulic pressure fromthe mandrel to the area between the ring and the anchoring means, saidmeans to admit hydraulic pressure to the area between the ring andshearable means including a hydraulic tool lowerable into the mandrel ona tubing string from the surface, said tool including a tubular Support,port means in the wall of the mandrel to admit hydraulic pressure to thesaid area, spaced seal members on the tubular support on opposite sidesof the port means arranged to seal against the wall of the mandrel, andport means in the tubular support between the seal members arranged toadmit hydraulic pressure from the surface through the tubing stringbetween the seal members.

References Cited UNITED STATES PATENTS 2,275,935 3/1942 Baker 166l202,352,423 6/1944 Church 166179 X 2,834,415 5/1958 Boer 166-196 X2,899,218 8/1959 Creighton 285302 3,181,614 5/1965 Brown 166--1223,191,682 6/1965 Cochran 166l20 3,329,214 7/1967 Ehlert 166-2263,330,357 7/1967 Elliston l66196 X CHARLES E. OCONNELL, PrimaryExaminer.

DAVID H. BROWN, Examiner.

